Condensed Consolidated Balance Sheet (Parenthetical) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	36,395,970	35,132,365
Common stock, shares outstanding	35,243,709	34,282,244
Treasury stock, shares	1,152,261	850,121